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1500 questions
18
votes
4 answers
What is the simplest UNIX system with a MMU?
I was recently looking at a Motorola 68010 and 68451 that have been in some ESD foam on a shelf for a very, very long time. Now, things are all so huge in memory, but BSD4.4-Lite can run in only 256k for the kernel with networking…
b degnan
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18
votes
2 answers
What made the Amiga "Genlock-able"?
Right at the moment the original Amiga A1000 was being introduced, Commodore was already advertising its ability to use a Genlock peripheral, and promising that Commodore's own Amiga 1300 Genlock would be "available soon". This must have been…
Brian H
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18
votes
3 answers
How did the Commodore 64 show a picture while reading cassette?
I was watching this video just now https://www.youtube.com/watch?v=I0YmJluYb6Q&ab_channel=NostalgiaNerd on things that early home computers displayed on the screen while reading cassettes, and reminded of something. The loading bars are easy to…
rwallace
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18
votes
3 answers
Did anyone ever put half a megabyte of memory in an Altair?
The Altair 8800 typically, at least in the early years after its release in 1975, operated with no more than a few kilobytes of memory, for the excellent and sufficient reasons that memory was expensive in those days and it was initially marketed to…
rwallace
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18
votes
3 answers
6502 ORA not updating the accumulator
Unless I'm reading the manual incorrectly, the following should produce $11 when D404 = $10 (I'm turning on the gate for voice1 which has been previously set to triangle wave %00010000/$10)
00153 5198 A9 01 LDA #01
00154 519A 0D…
Simon
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18
votes
4 answers
Raytheon 704 mini uses?
I came across this little machine in a roundabout fashion - 4kW of RAM and 1usec cycle for "under $10,000"! (not including ASR33)
It seems this is largely lost to history. Does anyone know what this machine was made for (it seems all too similar to…
Maury Markowitz
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18
votes
1 answer
Arcade game: pseudo-3D flying down a Death-Star-like trench
I cannot find any references to this game so maybe someone here will recall it:
It was a full-sized arcade cabinet with an aircraft-yoke type controller with fire buttons on the tip of the yoke. I seem to recall rubbery handles on the yoke that…
Maury Markowitz
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18
votes
1 answer
Game cartridge save-game battery lifetime
Some cartridges on older consoles (like on the SNES) had battery save in them, so you can turn off the console, come back some time later and continue where you left off.
These use an actual battery that powers the RAM so it basically never turns…
Bálint
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18
votes
4 answers
Historical price of ROM
Historical price charts for RAM are quite readily available, e.g. in the mid-seventies a ballpark figure was a penny a byte. What was the price of ROM (assuming you were getting the chips produced in quantities at least a few thousand) in that time…
rwallace
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18
votes
5 answers
What was the first programming language, other than Lisp, to have “short-circuiting” Boolean expressions?
(This question is, of course, another thrilling installment of “The history of expression evaluation”; see the previous episodes here and here.)
In many programming languages, the Boolean operators ∧ and ∨, however they are spelled (and, &&, or,…
texdr.aft
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18
votes
3 answers
When and where was the ‘dotted sequence of integers’ version numbering scheme invented?
Probably the most widespread software version numbering scheme in use today takes the form of a dotted sequence of integers. Variants of this scheme usually share the following characteristics:
Version numbers consist of at least two (often three,…
user3840170
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18
votes
3 answers
What does this line: `T=C/2=INT(C/2)` do? Why is it valid syntax?
I do not understand line 80 of the short Applesoft BASIC program below. Didn't even know it was possible to have a single instruction be T=C/2=INT(C/2). Naturally, I tried breaking this line up / various dissections, all of which broke the program…
Grant
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18
votes
2 answers
Why does the 6502 JSR instruction only increment the return address by 2 bytes?
Currently messing with 6502 assembly on a C64, and I don't understand why the JSR instruction is so weird.
According to the instruction table, JSR is a 3-byte instruction and only operates in absolute mode. However, JSR only increments the PC by 2…
Jeroen Jacobs
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18
votes
6 answers
Are there other examples of CPU architectures mostly compatible with Intel 8080 other than Z80?
When the Zilog Z80 was released, it was marketed as being mostly ISA compatible with Intel 8080, while also providing enhanced features.
Likewise, the CPU of the Nintendo Game Boy is a custom architecture designed by Sharp, (believed by the Game Boy…
nitro2k01
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18
votes
1 answer
Did any Mockingboard game use the VIA timers or interrupts?
There were only a small number of games that supported any of the Apple II sound cards such as the Mockingboard.
From those games that used the Mockingboard, did any of them utilize the on-board VIA's timers or interrupts for anything?
Or, were all…
cbmeeks
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